Getter container



Sept. 21, 1965 M. B. FARRAR GETTER CONTAINER Filed Oct. 1. 1962 INVENTOR. MILLARD B. FARRAR ATTORNEY United States Patent 3,207,295 GETTER CONTAINER Millard B. Farrar, Rocky River, Ohio, assignor to Union Carbide Corporation, a corporation of New York Filed Oct. 1, 1962, Ser. No. 227,373 2 Claims. (Cl. 206-.4)

This invention relates to a vacuum tube getter container, and more particularly to directional flash getter assemblies.

The invention provides a vacuum tube getter container consisting of a substantially horizontal metal ring of substantially U-shaped cross-section provided with at least one annular integral horizontally extending upper flange for more properly directing getter vapors to the intended places of deposit, while at the same time shielding undesirable locations from such deposits.

The use of getter materials in the manufacture of electronic devices is well known. Such materials are used to clean up the residual gases and vapors which remain in certain electronic devices after they have been partially evacuated. It is customary to position the getter material within the device by means of a metallic container. The container and getter material positioned therein are heated inductively to vaporize the getter material.

One of the major problems encounted when the getter material is vaporized is the subsequent condensation on various components of the electronic device. Some of these deposits are generally beneficial, for example, the deposition of getter materials on the inner surface of the glass envelope of a vacuum tube, while other deposits have a pronounced deleterious effect on the useability and quality of the electronic apparatus, for example, the deposition of getter material on the electrodes of a vacuum tube.

One of the several disadvantages of the so-called channel vent getter as is commonlyused in industry now, is that the practice of spot welding the getter assembly to the supporting element in the radio tubes must be made by passing current through that part of the getter assembly which contains the active getter material. This practice causes particles to become loose in the tube and is a most diflicult section to weld through and make a substantial joint.

The main object of this invention is to overcome dificulties encounterd in the prior art.

Another object is to provide an improved getter construction that is simple and economical to manufacture, and produces superior directional control of the getter flash.

Very briefly, this preferably is accomplished by providing the upper portions of the side walls of a substantially U-shaped channel ring getter container with integral horizontally extending flanges, which when heated control the direction of getter flash, preventing the vaporized getter material from depositing on critical parts of the vacuum tube. At the same time such flanges offer a point remote from the getter material where the very end of a support wire can be spot welded with little damage to the getter material.

The invention can be better understood by referring to the accompanying drawing, in which- FIG. 1 is an enlarged plan view of a getter container illustrating the invention;

3,207,295 Patented Sept. 21, 1965 FIG. 2 is a view in cross-section taken on line 22 of FIG. 1;

FIG. 3 is a plan view of a modification;

FIG. 4 is a section taken on line 44 of FIG. 3;

FIG. 5 is a plan view of .a preferred modification; and

FIG. 6 is a section taken on line 66 of FIG. 5.

As shown in FIGS. 1 and 2, the getter container 10 con sists of a ring 12 of substantially U-shaped cross-section provided with an upwardly extending annular wall 14 and a horizontally extending annular flange 16. Getter material 18, such as barium, is disposed in the bottom of the annular channel constituting such container. The container 10 is mounted on a support wire 20, the upper end of which is spot welded to the bottom of the horizontally extending flange 16 adjacent the outer rim thereof. The so-supported getter container is usually positioned in an electronic vacuum tube (not shown).

An additional advantage is aiIorded by the invention in that the support arm or stem can be so spot welded to the flange and not to the bottom or side of the channel getter as is usually done. This eliminates the possibility of partially sintering the getter material in the getter container while attaching the support wire thereto. However, protection of the vacuum tube components is achieved regardless of whether or not the support arm or stem is aflixed to the flange or to the bottom of the getter container channel.

In FIGS. 3 and 4, the getter container is provided with an inwardly extending flange 22 to which the upper end of support wire 20 is spot-welded.

In FIGS. 5 and 6, support wire 20 is spot-welded to outwardly extending flange 16, the ring being also provided with an inwardly extending horizontal flange 28.

With regard to the size of the flanges, the thickness should remain the same but the width can be variable with reason, e.g., the flanges have been .025" wide on test samples, but could have been .050" wide and performed equally well.

The flanges should be kept small to reduce the overall mass, because any increase in mass requires more heating in order to flash the getter. Preferred are the dimensions shown, but the width could be increased without too much effect. The flanges, particularly the outside flange picks up heat fast and this heat directs the flash upward, resulting in directivity for the vaporized barium deposit.

Thus, the width of the flanges could be increased thereby adding additional directivity, up to the point that the heat distribution becomes unbalanced during flashing of the getter.

The invention thus provides better directional control of the getter vapors, together with an ideal spot-welding area for the very end of the support wire prior to use.

Iclaim:

1. A vacuum tube getter container consisting of a substantially horizontal metal ring of essentially U-shaped cross-section providing an upwardly opening channel the inside of which provides an annular support for getter material, the entire annular upper surface of which material is exposed to the region above the ring, said ring being provided with a continuous annular integral horizontally extending upper flange projecting outwardly substantially at right angles to the adjoining wall of such channel to provide optimal directional control of the getter vapors when said ring is heated to flash such getter material.

2. A vacuum tube getter container as defined by claim 1, in which said ring is supported by a vertical Wire the upper end of which is spot welded to the bottom of said flange.

References Cited by the Examiner UNITED STATES PATENTS 4 2,913,102 11/59 Pennoyer 206-0.4X 3,15 1,736 10/64 Della Porta 2060.4

FOREIGN PATENTS 1,054,183 4/59 Germany.

THERON E. CONDON, Primary Examiner.

EARLE J. DRUMMOND, Examiner. 

1. A VACUUM TUBE GETTER CONTAINER CONSISTING OF A SUBSTANATIALLY HORIZONTAL METAL RING OF ESSENTIALLY U-SHAPED CROSS-SECTION PROVIDING AN UPWARDLY OPEINING CHANNEL THE INSIDE OF WHICH PROVIDES AN ANNULAR SUPPORT FOR GETTER MATERIAL, THE ENTIRE ANNULAR UPPER SURFACE OF WHICH MATERIAL IS EXPOSED TO THE REGION ABOVE THE RING, SAID RING BEING PROVIDED WITH A CONTINUOUS ANNULAR INTEGRAL HORIZONTALLY EXTENDING UPPER FLANGE PROJECTING OUTWARDLY SUBSTANTIALLY AT RIGHT ANGLES TO THE ADJOINING WALL OF SUCH CHANNEL TO PROVIDE OPTIMAL DIRECTIONAL CONTROL TO THE GETTER VAPORS WHEN SAID RING IS HEATED TOO FLASH SUCH GETTER MATERIAL. 